Oil burning apparatus



1 0, 1940. H; B; DQNLEY 2,21 ,664

vQIL BURNING APPARATUS Filed April 26. A 1937 measm 0.1w

UNITED STATES PATENT OFFICE OIL BURNING APPARATUS.

Harold B. Donlcy, Columbus, Ohio. 'assignor to Columbus Metal Products Inc., Columbus, Ohio,

a corporation of Ohio ApplicatiohAptilZG, 1937, Serial No. 138,975

'rcumi. (cuss-91) i This invention relates to improvements in oil burners, and more particularly to oil burners of the vaporizing or hydroxylatins time. Amon the objects of the invention, I aim to provide a 6 safe, economical and eflicient burner of the type indicated wherein the burner an unusually wide range of operation by which the burner is adapted for high and low stages of combustion without involving the use of ignition or pilot flames for eilecting or sustaining low stage operation, and wherein clean steadily maintained combustion is provided at all stages, accidental flame extinguishing avoided and smoke or soot formation precluded or rendered internal diameter of the base chamber, the walls of said duct being formed with rows of spaced openings of such number,'arrangement and pro- 30 portion as to admit controlled amounts of air into the duct to either hydroxylate gaseous fuel mixtures passing through the duct or to eifect complete combustion of such mixtures. depending upon the stage of operation of the burner.

I 35 Another object of the invention resides in the provision of a mechanically simplifled type of burner which is easy to clean and maintain in proper working condition.

For a further understanding of the invention, 40 referenceis to be had to the following description and the accompanying drawing, wherein;

Fig. 1 is a vertical sectional view taken through a vaporizing oil burner constructed in accordance with a preferred form of the present invention;.

4 Fig. 2 is a horizontal sectional view taken throughthe burner on the plane indicated by the line II-JI of Pig. 1. I

Fig. 3 is a vertical longitudinal sectional view taken through a storage type water heater pro- 50 vided with-a burner constructed in accordance with the present invention.

Referring more particularly to the drawing, the numeral l designates the improved oil burner comprising the'present invention in its entirety.

65 Theburnermaybeadaptedformanyusesaafor instance, the heating of hot water tanks,.in the construction of room or space heaters or in dentralized house heating plants, the sizeor capacity thereof. varying with the heat requirements of the apparatus or systems associated therewith. v In the particular embodiment of the invention illustrated, the burner comprises a vessel or, vaporizing pot 2, which is preferably formed from sheet metal and includes a closed bottom wall 3, an annular side wall I; and an inwardly and sub- 10 stantially horizontally extending top wall 5. The walls 3, 4 and 5 define an enlarged oil-receiving and vaporizing chamber 6. Oil from. any suitable source of supply may be introduced into the bottom'of the vessel by means of a pipe line 'I in which may be installed a conventional constant level or metering device 8, whereby the quantity of fuel delivered to the burner may be controlled. The wall 4, adjacent to the upper part thereof, is

provided wltha plurality of restricted air inlet openings 8, which openings are arranged above the level of the pool of oil which is normally present in the bottom of the chamber 8. The number of the openings 9 and their total area is such that but limited quantities of air may enter the chamber therethrough, the'amount of air being suiflcient to combine with oil vapors or gases to provide a hydroxylated'fuel 'mixture but insuiilcient to support complete flame producing combustion of any appreciable character.

The top wall I is provided centrally with an opening it and disposed in registration with this opening and arising axiallyirom the wall 5 is a cylindrical open-ended duct II, the latter being of substantially the same 'diameter as the opening ill but of considerably smaller diameter than the internal diameter of the chamber 8. The lower end of the duct ll immediately above the opening or outlet ll of the chamber 0 is formed with a row of spaced openings l2, and the upper end of said duct is provided with a corresponding row of openings ll. 'ings l2 and It, the duct is'further formed with a Between the rows of openthe lower end of said duct, the flame being characterized by inwardly extending pencils of blue or luminous flame, which appear to extend inwardly from the openings l2. This limited flame comp This limited low capacity or low stage combustion is efiectedwith the aid of a hydroxylated gaseous fuel mixture, since the oil vapors are hydroxylated by the amount of air admitted into the vessel through the openings 9. This low stage combustion is steadily maintained and extinguishment thereof prevented by the inclusion of the cylindrical, straight walled duct H, the top wall 5 and the enlarged gas generating chamber 6.

When additional amounts of fuel are introduced into the burner to promote high stage or high capacity combustion, wherein the maximum heat output of the burner is evolved, the amount of air passing into the duct through the openings l2 and M is insuificient to support complete or visible flame combustion, so that the openings I2 and I4, like the openings 9, merely provide sufflcient air inflow to hydroxylate the increased quantity of oil vapors during the passage ofsuch oil vapors throughout the major portion of the length of the duct. Complete combustion of the fuel mixture when the burner is operating at maximum capacity is provided by the admission of air through the openings l3 and/or from air obtained from atmospheric sources above the top of the duct H, so that during high capacity operation, the visible flame observable is disposed immediately at the top of the duct or above the same.

Surrounding-the duct I I is an annular casing l5, which is suficiently spaced from the walls of the duct l I to provide a circular air space I6. Air may be delivered into the space l6 either by natural or forced flow through a pipe member I6a extending laterally from the casing [5 to the atmosphere exteriorly of the burner. The top wall I I of the casing I5 is connected with a curved "goose neck conduit I8 which has its outer end terminated in a conical head [9 arranged above and in axial registration with the top of the duct II. The head I9 is perforated as at 20, so that air passing through the conduit l8, and obtained from the space I 6, issues through the perforations in the head l9 to combine with the fuel mixture existing from said duct whereby to cause efficient flame producing combustion thereof.

The burner, as" a .whole, may be positioned within the bottom of a heater casing 2|, and to the top of this casing there is connected an outlet flue 22, in which is arranged an automatic draft regulator 23 to control the draft pressure of the burner. The operating characteristics of the burner are improved by the provision of a ring 24; which is positioned on the top wall I! of the casing I5 and overhangs the interior of the duct II, the said ring eliminating down drafts which might otherwise interfere with the outflow of air through the openings I 3 or other air admitting openings disposed at lower positions within the duct.

The burner mechanism described is characterized by its wide combustion range or turn-down ratio. No pilot flame is necessary to sustain the operation of the burner under low-fire conditions, 1. e., low-stage operation. However, at all stages of operation, hydroxylation of the fuel mixture takes place prior to complete combustion thereof. Thus at low stage operation, the openings 9 constitute primary air inlets and the openings I0 secondary air inlets, the openings 9 providing air for hydroxylation and the openings l0 air for complete combustion. However, on high stage operation, the openings 9, i0 and II, and possibly to a limited extent the openings 13, all become primary air inlet openings to produce hydroxylation of the fuel mixture, secondary associated upstanding duct II, which causes low fire combustion within the bottom of I the duct l I, providing for the sustained evolution of oil vapor from the pool of oil delivered to the bottom wall 3 and the thorough mixture of such oilvapor with air entering through the openings 9 prior to complete combustion. Moreover, the shape of the burner protects these operations against down drafts tending to detrimentally aflectlow. stage combustion. v

The duct ll may be formed from a chromium nickel alloy steel inorder that it may successfully withstand high combustion temperatures, so that active flame producing combustion may take place within the confines of the duct when the burner is operating at its maximum capacity. This has the advantage of permitting lower grades of furnace oil (fuel oil) to be used as the operating fuel since the high internal temperatures within the duct are transmitted to the pool of oil in the bottom of the chamber 6 and thereby assist in its vaporization and/or gasification.

An exterior casing 25 surrounds the to protect it from drafts which would tend to produce uneven temperatures in the wall 41. The

casing 25 also provides a substantially constant The reduced? opening 26 in the bottom of the casing provides supply of air to the openings 9.

for the entrance of air into the casing without causing objectionable air currents.

The pipe l6a extends through thewa'll of the exterior casing 25 and serves to conduct air at atmospheric temperatures and pressures to the chamber l6. Air flow through the pipe iBa is burner l established by the suction created within the I chamber through the consumption of air by the flame and upward movement through the conduit 18. Satisfactory results have been obtained when air was permitted to flow by natural circulation through the pipe 16a but it is within the concept of the invention to connect the outlet of a blower with the outer end of the pipe if positive flow of air is desired.

What is claimed is:

1. In oil burning apparatus, an oil receiving and vaporizing vessel having, bottom, side and top walls, said top wall being formed with an opening, an elongated tubular duct arising vertically from the top wall in registration with the opening therein,said duct beingmateriallysmaller in diameter than said vessel, a row of primary air inlets formedin the side wall of said vessel adjacent t-he top wall thereof, a plurality of longitudinally spaced rows of air inlets formed in the wall of said duct, an annular wall surrounding said duct and spaced therefrom, a casing spaced .from and surrounding said vessel and annular wall, said casing being formed with an opening at the lower end thereof, a top wall extending from said duct to said casing to provide annular concentric chambers, and conduit means leading from the inner chamber to the atmosphere.

2. Oil burning apparatus comprising a combustion vessel having bottom, side and top walls, said side wall having a row of openings adjacent its upper end and said top wall being formed with a centrally disposed opening a duct arising from the top wall of said burner in registration with the opening therein, said duct being formed with vertically spaced. rows of air admitting openings, a wall structure surrounding'said duct and spaced therefrom to provide a closed annular chamber, a casing surrounding said combustion vessel and spaced therefrom to provide a second annular chamber having an opening in the bottom wall smaller in diameter than said vessel, the openings in the side wall of said combustion vessel being in communication with the atmosphere through the chamber surrounding said vessel to supply air at atmospheric pressure to said vessel, reduced tubular means for introducing air into the chamber surrounding said duct, and means for introducing liquid fuel to said combustion vessel.

3. Oil burning apparatus comprising a com- 9 of said duct, said head being in communication.

with said annular chamber, a casing surrounding said combustion vessel and spaced therefrom to provide a second annular chamber having an opening in the bottom wall smaller in diameter than said vessel, the opening in the side wall of said combustion vessel being in communication I with the atmosphere through the chamber surrounding said vessel, reduced tubular means for introducing air into the chamber surrounding said duct, and means for introducing liquid fuel to said combustion vessel.

4. Oil burning apparatus comprising a combustion vessel having bottom, side and top walls, said side wall having a row of openings adjacent its upper end and said top wall being formed with a centrally disposed opening, a duct arising from the top wall of said burner in registration with the opening therein,said duct being formed with vertically spaced rows of air admitting openings, a wall structure surrounding said duct and spaced therefrom to provide a closed annular chamber, a casing surrounding said combustion ,vessel and spaced therefrom to provide a second annular chamber having anopen bottom, the openings in the side wall of said combustion vesselbeing in communication with the atmosphere through the chamber surrounding said vessel to supply air at atmospheric pressure and temperature to said vessel, reduced tubular means for introducing air into the chamber surrounding said duct, and

means for introducing liquid fuel to said combustion vessel. I

5. Oil burning apparatus comprising a horizontally disposed ring, a cup-shaped vessel carried cal duct extending from said partition wall in registration with the opening therein to the opening in said ring, the partition wall and duct serving to divide said cup-shaped vessel into combustion zone, outlet duct and annular air chamber, said duct wall being formed with air admitting openings, means for introducing liquid fuel to said cup-shaped vessel, means for introducing air to the air chamber in said vessel, and a casing surrounding'said vessel and spaced therefrom to provide a second air chamber open-at its lower end to the atmosphere, the openings in said vessel wall establishing communication between said combustion zone' and the atmosphere through said'second air chamber.

6.. In oil burning apparatus, an oil receiving and vaporizing vessel having bottom, side and top walls, the latter being formed with an'opening, a tubular duct extending upwardly from said top wall in registration with the opening therein, a plurality of primary air admitting openings formed in the side wall of said vessel below the top wall thereof, said duct having spaced rows of air inlets provided therein, an annular wall extending upwardly from said vessel in spaced relation from said duct, a second annular wall spaced from and surrounding said vessel and said first annular wall, a substantially horizontal wall extending from the outer annular wall to said duct and closing the upper ends of the air spaces formed by the annular walls and said duct, the outer space being open to the, atmosphere at the lower end, means for supplying air to the inner air space, a distributor head supported by said horizontal wall in registration smaller in diameter than said vessel, 9. row of primary air inlets formed in the side wall of said vessel adjacent the top wall thereof, a plurality of longitudinally spaced rows of air inlets formed inthe wall of said duct, an annular wall surrounding said duct and spaced therefrom, a casing spaced from and surrounding said vessel and annular wall,said casing being formed with an opening at the lower end thereof, a top wall extending from said duct to said casing to provide annular concentric chambers, a ring-member carried by the last-mentioned top wall and extending inwardly beyond the walls of said duct to reduce the outlet thereof and eliminate back drafts, and conduit means leading from the inner chamber to the atmosphere.

HAROLD B. DONLEY. 

